Model Q46H/79PR Total Chlorine Monitor from ATI


The basic sensing element used in the Q46H/79PR Total Chlorine Monitor is a 3-electrode amperometric membrane sensor which measures chlorine directly. The chlorine measurement does not alter the sample or add any chemicals to the sample stream, so the water flow can return to the system if desired. In addition to total chlorine measurement, the Q46/79PR is also available with an optional pH input which provides two parameter monitoring system.


  • Total chlorine – membraned covered amperometric sensor that measures total chlorine without the addition of pH buffer, iodide solution or other reagent. The total chlorine sensor can be tank mounted with a submersion assembly or flow cell mounted for sampling applications
  • Optional pH sensor – Active pH measurement with choice of pH sensor types. Selecting this option converts the monitor to a dual analyzer, providing 4-20 mA outputs for both chlorine and pH.
  • Flexibility – Programmable range options from 0.1ppm to 200.0ppm through 3 internal automatic ranges. User ranges of 2.000ppm, 20.00 ppm or 200.0 ppm
  • AC or DC power options – Available in either 90-260 VAC or 12-24 VDC supply systems. All features remain the same in both variations.
  • Analog output options – Two analog outputs may be configured to track chlorine and temperature, chlorine and chlorine or chlorine and pH. Both analog outputs can be individually programmed to fail to specific values. An optional 3rd output is available for tracking all three parameters.
  • PID output – PID controller can be configured as one of two outputs. PID includes manual operation feature, and diagnostic “stuck-controller’ timer feature for relay notification of control problems.
  • Digital communications – Available in either Profibus-DP or Modbus RTU.
  • Relay contacts – Three 6 amp SPDT relays and two analog 4-20 mA outputs are standard. Software settings for relay control include setpoint, deadband, phase, delay and fail safe. An optional 3-relay card, for 0-30 VDC signals is available to bring the total to 6 relays.
  • Easy to install – We can supply the Q46H/79PR complete with sample flow controls mounted to a PVC back plate ready to mount. Connect power, water sample and analog/relay outputs and you are ready to go. Systems are available with or without a flow switch for remote indication of loss of sample.

Two types of chlorine sensors are available. One id designed for flowcell installation and the other is for submersion applications. Total chlorine monitoring below a concentration of 0.5 ppm should be done using a flowcell system. Good control of sample flow and pressure is important for accurate measurement. The standard constant-head flowcell should be used for most applications. A sealed flowcell and a low volume flowcell are also available for special applications. Submersible total chlorine sensors can be used for measuring total chlorine in wastewater effluent or other open channel applications. Direct measurement with a submersible sensor can provide a dependable monitor without all the sampling and chemicals associated with traditional total chlorine measurement.

Standard Q46H/79PR Systems are AC powered or a DC powered version is also available. The basic system includes two isolated 4-20 mA outputs and three SPDT alarm relays.

If pH measurement is also desired, an optional pH sensor is available. With this sensor connected, the second analog output may be configured for pH instead of temperature to provide a dual chlorine/pH monitoring system.

Q46h/79PR systems may also be supplied with an additional output board. This output board may contain either a third 4-20 mA output or three additional low power relays. Adding a third analog output is the most common as the system then provides isolated outputs for chlorine,pH and temperature.

Specifications – Electronic Monitor

Range  0-2.000, 0-20.00, 0-200.0 ppm
Accuracy ±0.05 ppm
Repeatability ±0.02 ppm
Zero Drift < 0.01 ppm per month
Display Large 4 digit LCD main display, 0.75″ characters, 12 digit alpha-numeric second line
Control Relays Three SPDT relays, 6A @ 250 VAC
Three additional SPST low voltage relays optional
Analog Output Two isolated 4-20 mA, 500 Ohms max load, assignable
Temperature 0-50°C
Power 110-240 VAC, 50/60 Hz, 10VA max
12-24 VDC, 500 mA max, optional
Enclosure NEMA 4X (IP-66) Polycarbonate, V-0 flammability
Weight 6 pounds with sensor, flowcell & accessories
15 pounds assembled into panel

Specifications – Sensor & Flowcell

Sensor Membrane covered amperometric
Optional pH Sensor Combination pH sensor with or without preamplifier
Materials PVC & 316 SS
Response Time 90% in 60 seconds
Temperature Limits 0-50°C
Pressure Limit 0-50 psig
Sensor Cable 25′
Sensor Flowcell Clear acrylic constant head overflow standard
Sealed acrylic flowcell optional
Sample Flowrate 7-15 GPH (0.5-1.0LPM)

Ordering Information

For pricing please call AFC International at 800-952-3293, 219-987-6825 or fax 219-987-6826 or email

Catalog No.
Series Q45H/79PR Total Chlorine Monitor, 120 VAC, constant head flowcell & 25′ cable
Series Q45H/79PR Total Chlorine Monitor, 120 VAC, submersible sensor & 25′ cable


Series Q46H/79PR Total Chlorine Monitor datasheet

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